What is the usage of deletelater in Qt?

In Qt, the deleteLater() function is used to delete a QObject object at a later point in time. It provides a safe way to delete the QObject object to ensure that the deletion operation only occurs after the object’s slot functions have been executed.

The deleteLater() function schedules the destruction of a QObject object for a later point in time within the event loop. It does not immediately delete the object, but rather queues the deletion operation for processing by the event loop.

The advantage of using the deleteLater() function is that, in multi-threaded or asynchronous operations, you can avoid potential issues caused by accessing a deleted object while deleting it. It is safe to call deleteLater() in the object’s slot function because it ensures that the object deletion occurs after the slot function is completed.

Here are some common uses of the deleteLater() function:

1. Call deleteLater() in the slot function of the QObject object to delay the deletion of the object.

void MyObject::mySlot()
{
    // 处理槽函数的逻辑
    // ...

    // 删除对象
    deleteLater();
}

1. Use the QObject::connect() function to connect deleteLater() with other signals, in order to delete the object under certain conditions.

QObject::connect(someObject, &SomeClass::someSignal, objectToDelete, &QObject::deleteLater);

Please note that the deleteLater() function can only be used for objects of classes that inherit from QObject. If you need to delete a non-QObject object, you should use the delete operator instead of the deleteLater() function.